Ein einfacher Zugang zu den tetracyclischen Vorläufern der Hetero‐ und Secoyohimbane, Strychnos‐ und Oxindolalkaloide

Abstract

A Simple Entry into the Series of Tetracyclic Hetero-and Secoyohimbanes, Strychnos and Oxindole AlkaloidsThe divinylogous urethane 4a reacts in diluted acetic acid to give the indolochinolizine 9 (yield 40%). The

Catalyst-free, one pot and three-component synthesis of 4′-phenyl-1′H-spiro[indoline-3,2′-quinazolin]-2-ones and 2,4-diphenyl-1,2-dihydroquinazolines

“…A spirooxindole system is also a core scaffold of many synthetic pharmaceuticals with a wide range of biological applications such as antimicrobial, 14 antitumor, 15 antibiotic 16 and inhibitors of the human NK-1 receptor. 17 Due to the significant biological activity of these spiroxindoles, it is required to find new and simple synthetic methods for the preparation of new substituted spirooxindoles. Owing to extensive applications of diverse quinazoline derivatives in various fields, several methods have been reported such as copper-catalyzed cascade coupling of 2-bromobenzaldehyde with acetamidine hydrochloride, 18a coppercatalyzed Ullmann N-arylation coupling, 18b,c photochemical method, 18d tandem reaction from 2-aminobenzophenones and benzylic amines, 18e,f maltose-urea-NH 4 Cl mixture as a solvent synthesis, 18g copper-catalyzed alkynylation and cyclization of Nphenylbenzamidines, 18h the condensation of aldehydes with 2-aminobenzylamine using sodium hypochlorite 18i or MnO 2 18j as…”

Synthesis of spiroimidazopyridineoxindole, spiropyridopyrimidineoxindole and spiropyridodiazepineoxindole derivatives based on heterocyclic ketene aminals via a four-component reaction

“…2 Spirooxindoles are a key structural element in a wide range of natural products with biological activities. 3 They have attracted signicant attention due to their useful pharmacological properties and biological activities including antimicrobial, 4 anti-tumor, 5 anti-tubercular, 6 anti-inammatory, 7 anti-HIV, 8 anti-fungal, 9 the action as inhibitors of the human NK-1 receptor, 10 anti-cancer, 11 antibiotic, 12 and anti-malarial. 13 Spirocyclic oxindoles containing a six-membered moiety, especially a six-membered piperidine structure at the C-3 position, have a wide spectrum of biological activities; examples include the non-peptidyl growth hormone secretagogue MK-0677 (ref.…”

Ultrasound‐assisted synthesis of novel spiro[indoline‐3,5′‐pyrido[2,3‐d]pyrimidine] derivatives using Fe3O4@Propylsilane@Histidine[HSO4−] as an effective magnetic nanocatalyst

“…Indole is the core structure of many natural products and medicinal agents that show antiparasitic, antibacterial, antimicrobial, antimycobacterial, antitubercular, anticancer, analgesic, and anti‐HIV activities . Furthermore, it has been reported that formation of spiroindoline derivatives via the indole 3‐carbon atom can highly enhance biological activity …”